Video card memory needed for 10 bit color on 2560x1600 display

[Wakatipu]

I have an XFX R9 270x video card with 2GB of video memory. Using a Display Port cable I have been able to operate a monitor with 2560x1440 resolution at 10 bit color depth according to the Catalyst 14.12 driver. I have switched to a 2560x1600 display also running through the DP cable, but now Catalyst reports the color depth as being 8 bits.
Could this be due to my video card not having sufficient video memory for the greater resolution of the new display?
If so, could someone describe the math that I would do to figure out how much more video memory is called for?
If this is not the problem, does anyone have a suggestion?

 

[Stuka87]

Chances are your display doesn't support 10bit. What model display is it?

 

[sheh]

It might be just a driver issue, or a need to use a custom resolution.

There's no practical resolution that can exhaust the memory on any graphics card capable of outputting it.

2D doesn't need much memory. Multiply the number of pixels by the bit depth including alpha, probably rounded up to the next whole byte or power of 2 bytes. Multiple by 2 for double buffering, but let's assume the OS may use more because of the fancier desktop composition in modern Windows versions, so say 4. Maybe multiply again for unknown extra stuff, and that's more or less what I'd expect you'd need.

So let's say: 2560x1600 * (30-bit color + 10-bit alpha rounded up to next power of two, in bytes = 8) * 4 * 2 = 256MB

 

[Black Octagon]

Chances are your display doesn't support 10bit. What model display is it?

This

 

[Wakatipu]

The monitor is a Monoprice unit they identify by the ID number 10734. It is an IPS LED backlit unit. The Monoprice website does not identify the color depth capability of the unit.

The email I sent to Monoprice tech support yesterday asking about this has not yet been responded to.

There was a recent review on Tom's Hardware

http://www.tomshardware.com/reviews/monoprice-30-inch-led-monitor,4046.html

identifies the monitor as having an LG panel with 10 bit color depth and capable of covering 91.8% of the Adobe RGB color space.

I also sent an email yesterday to the review author asking for confirmation of the 10 color bit depth spec. I have not yet received a reply. I would think that the test equipment they used to make the review would have the ability to correctly identify the color depth capability of the monitor. But I am not familiar with the Calman equipment since I use a different product for my color calibration work.

 

[Black Octagon]

Hmm, that indeed would appear to be a true "10-bit" (8-bit + FRC) panel. The only 30" 2560x1600 AH-IPS panel in TFTCentral's database is the LM300WQ6-SLA1. That's the same 10-bit panel used in the Dell U3014.

THAT SAID, actually using 10-bit color depth requires a few things other than a monitor:
- Dual Link DVI or DisplayPort (check)
- Appropriately 10-bit 'aware' software (check?)
- A compatible graphics card...

Regarding that last point, your 270x most likely does not cut it. AFAIK, you'd need a workstation GPU like the FirePro series. More here: https://www.amd.com/Documents/10-Bit.pdf

Can I ask why you want to use this color depth? Is it just curiosity or do you have a genuine need for it?

 

[3DVagabond]

IIRC AMD does now support 10bit in their consumer cards. I don't remember which driver added it. Just checked and it was CAT 14.6 that added it.

 

[Black Octagon]

IIRC AMD does now support 10bit in their consumer cards. I don't remember which driver added it. Just checked and it was CAT 14.6 that added it.

Hey you're right! I missed that. Thanks.

In this case, OP, I suggest that you direct your query to AMD tech support, as it might be a driver-configuration thing.